<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_CSS显示模式</title>
  <style>
    div{
      width: 200px;
      height: 200px;
      border: 2px solid black;
    }
    span{
      width: 200px;
      height: 200px;
      background-color: grey;
      display: block;
    }
    input,button{
      width: 200px;
      height: 200px;
      display: inline-block;
    }
    .d2:hover{
      display: none;
    }
  </style>
</head>
<body>
    <div class="d1">111</div>
    <div class="d2">222</div>
    <div class="d3">333</div>
    <hr>
    <span>123456789</span>
    <span>123456789</span>
    <span>123456789</span>
    <hr>
    <input type="text">
    <input type="text">
    <input type="text">
    <input type="button">
</body>
</html>